vexer vs vex

vexer is a noun but vex is not a noun.

Word	Noun	Adjective	Verb	Adverb
vexer	Yes	No	No	No
vex	No	No	Yes	No

vexer (noun)	vex (noun)
someone given to teasing (as by mocking or stirring curiosity)

vexer (verb)	vex (verb)
	be a mystery or bewildering to
	subject to prolonged examination, discussion, or deliberation
	change the arrangement or position of
	cause annoyance in; disturb, especially by minor irritations
	disturb the peace of mind of; afflict with mental agitation or distress